As the author of this article says, you don’t need to be a neurologist to understand the how and why of exercise’s effects on your brain.
In the same way as you don’t need to be a cardiologist to understand its impact on your heart health.
We are very good at measuring the physical benefits of exercise.
The mental health benefits? Not so much.
If we know that exercise improves our brain health, wouldn’t it be useful to have a measure of this improvement? That way, we could establish what works best.